The field of network security has become increasingly important in today's society. The Internet has enabled interconnection of different computer networks all over the world. The ability to effectively protect and maintain stable computers and systems, however, presents a significant obstacle for component manufacturers, system designers, and network operators. This obstacle is made even more complicated by the continually evolving array of tactics implemented by malicious operators. If certain types of malicious software can infect a host computer, it may also be able to perform any number of hostile, intrusive, or annoying actions, such as sending out spam or malicious emails from the host computer, stealing sensitive information from a business or individual associated with the host computer, propagating to other host computers, and/or assisting with distributed denial of service attacks, for example. In addition, the malicious operator can sell or otherwise give access to other malicious operators, thereby escalating the exploitation of the host computers. Hence, significant challenges remain for developing innovative tools to combat tactics that allow malicious operators to exploit computers.